Check that UDP initial values on non-registered outputs generate compile
errors for both old-style and ANSI-style UDP declarations. Also check that
conflicting UDP port declarations generate an error and that a valid
ANSI-style `output reg` initializer is accepted.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Malformed UDP declarations can reach `pform_make_udp()` with conflicting
duplicate port declarations or with an initial value on an output that was not
declared as a register. These cases currently trigger internal assertions
instead of reporting normal compile errors.
The ANSI-style UDP output initializer path also treats the initializer
expression as if it was the old-style `initial out = value` assignment
statement. This makes a valid `output reg out = 1'b0` initializer assert as
well.
Report errors for the invalid declarations and read the ANSI-style initializer
value directly from the initializer expression.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Check that enum item names can shadow visible type identifiers. Cover plain enum
items as well as the counted and ranged enum item sequence forms.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
SystemVerilog allows a declaration in an inner scope to use the same name as a
type identifier from an outer scope. This also applies to enum item names. The
lexer reports such names as `TYPE_IDENTIFIER` before the enum item has been
installed, which made constructs such as:
typedef int T;
module test;
enum { T = 1 } e;
endmodule
fail in the enum item grammar.
Enum item declarations do not have the local type/name ambiguity that exists for
variable, net, or parameter declarations. The name in each `enum_name`
production is always the enum item name, including the sequence forms like
`T[2]` and `T[1:2]`. Use `identifier_name` for these names so they can shadow a
visible type identifier.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Check that function and task declarations can use a visible type identifier as
the declaration name. Cover both ANSI declarations and the non-ANSI forms where
the name is parsed without a separate return type or port list.
Also check class method declarations where the method name is the same as the
enclosing class name. Add GitHub issue #670 coverage for the `function void`
case using the issue-based regression naming scheme.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
SystemVerilog allows a declaration in an inner scope to use the same name as a
type identifier from an outer scope. This also applies to task and function
names. The lexer reports such names as `TYPE_IDENTIFIER` before the new task or
function has been installed, which made constructs such as:
typedef int T;
module test;
function int T(input int value);
return value;
endfunction
task T;
endtask
endmodule
fail in the task and function declaration grammar. A class method with the same
name as the class itself hits the same problem because the class name is visible
as a type identifier in the class scope.
The task grammar can accept `identifier_name` directly, because a task has no
return type and the token after `task` and the optional lifetime is always the
task name.
Function declarations have a local return-type/name ambiguity. After
`function T` the parser does not know yet whether `T` is the function name with
no explicit return type, or whether a following identifier will make `T` the
explicit return type as in `function T f`. Parse the optional function return
type and function name together. This allows a `TYPE_IDENTIFIER` token to be
interpreted as the function name when no separate function name follows, while
still parsing typed forms and `void` return types correctly.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Check that visible type identifiers can be shadowed by value parameter names
and by type parameter names. Cover ordinary parameter declarations, typed
parameter declarations, and parameter port list declarations separately.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
SystemVerilog allows a visible type identifier to be shadowed by a
parameter declaration name. Parameter declarations still required the
parameter name to be an `IDENTIFIER` token and rejected declarations like:
typedef int P;
module test;
parameter int P = 1;
endmodule
The parameter grammar can not just accept `TYPE_IDENTIFIER` in every name
position. After `parameter P` the parser does not know yet whether `P` is
the parameter name, or whether a following identifier will make `P` the
parameter type.
Parse the optional value parameter type and the first parameter assignment
together. This allows a `TYPE_IDENTIFIER` token to be interpreted as the
parameter name when no explicit type is present, while still parsing a
following identifier as the parameter name for typed parameters.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Check that a class property can have the same name as a type declared in
an outer scope, or a type imported through a wildcard import. Also check
that a class property can have the same name as the class itself.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
SystemVerilog allows a class property to have the same name as a visible
type. The lexer reports the visible type name as `TYPE_IDENTIFIER` before
the property has been installed, which made constructs such as
`typedef int T; class C; int T; endclass` fail in the class item grammar.
A class property with the same name as the class itself hits the same
problem. Member references such as `obj.T` or `obj.C` can also hit the
same tokenization problem in hierarchical names.
Parse class properties through the same declaration helper used for
variables so the first type/name pair can be disambiguated. Also let
hierarchical member names use `identifier_name`.
Stop type lookup when a class scope already has a property with the same
name. This makes method body references resolve as properties instead of
visible types, including type names found through wildcard imports.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Check that automatic variables referenced through an assignment pattern in a
procedural `force` statement are rejected.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Assignment patterns contain child expressions, but currently inherit
`PExpr::has_aa_term()` which always returns false. This means automatic
variables inside a pattern are not caught by checks for procedural `force`
and procedural continuous assignment statements.
Implement `has_aa_term()` for `PEAssignPattern` and recurse into all pattern
elements.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Check that the repeat count expression of a non-blocking intra-assignment
event control can reference an automatic task argument. The repeat count is
evaluated when the assignment is scheduled, so the automatic variable is not
referenced after the task scope is freed.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
The repeat expression of an event controlled non-blocking assignment is
evaluated once when the assignment is scheduled. This means there is no
risk of it being referenced when its scope has already been freed. And
hence there is no need to require the repeat expression to only contain
static terms.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Check that variable and net declaration names can shadow a visible type
identifier. Check this for explicit data type declarations, `var` declarations,
and net declarations.
Check that task and function formal argument names can shadow a visible type
identifier, and that typed arguments still use the visible typedef when an
argument name follows.
Check ambiguous module port declarations where a type identifier can be either
the port name or the port type, with and without dimensions, and that
declaration lists continue to use the type selected by the first ambiguous
declarator. Cover both ANSI and non-ANSI module port declarations.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
SystemVerilog allows a declaration in an inner scope to use the same name as a
type identifier from an outer scope. The lexer reports such names as
`TYPE_IDENTIFIER` before the new declaration has been installed, which made
constructs such as `int T;`, `wire T;`, and `input T` fail when `T` was a
visible typedef.
The affected declaration forms have a local type/name/dimension ambiguity. For
example, after `input T` or `wire T` the parser does not know whether `T` is the
declared name, or whether a following identifier will make `T` the declaration
type in `input T x` or `wire T x`. With dimensions, `input T [1:0]` and
`wire T [1:0]` can be either a declaration named `T` with unpacked dimensions or
a declaration using typedef `T` as a packed type followed by another name.
Parse these declaration forms with productions that decide the first declarator
and carry the selected declaration type across the rest of the list. This covers
variable declarations, net declarations, ANSI and non-ANSI module port
declarations, and task/function port declarations. Other identifier uses still
need separate grammar changes.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Check that a blocking intra-assignment delay on a real value preserves the
assigned value after the delay.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
The vvp parser did not accept the local flag on `.var/real`
declarations. This can happen when elaboration creates a compiler-generated
real temporary, for example when a blocking intra-assignment delay is
rewritten from:
r = #1 1.25;
to assign the right hand side to a temporary before the delay and assign
the temporary to the target after the delay.
Add support for the local flag. Keep a VPI symbol for the variable so
`%load/real` can still resolve the label, but do not attach local real
variables to the current scope.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Check that visible type identifiers can be shadowed by declarations in
other namespaces or nested scopes. Keep each grammar category in a
separate regression so failures identify the affected rule.
Also check that package import and export items can name a type
identifier.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
SystemVerilog allows an identifier that is visible as a typedef to be
shadowed by a declaration in a nested scope or reused as a declaration
name in another namespace. The lexer can return `TYPE_IDENTIFIER` before
the new name has been installed, so these grammar positions reject
otherwise valid code.
This is not a complete conversion of all identifier grammar sites. Only
handle the trivial conflict-free cases where `IDENTIFIER` can be replaced
by `identifier_name` without any surrounding grammar changes.
Also stop type lookup when the current scope already has a local symbol
with the same name. This makes later references to a shadowing
declaration use the local symbol instead of an outer typedef.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
The string substr() method reports an error if it is called with the wrong
number of arguments, but the error was not counted and elaboration continued
with missing function arguments. A call such as `s.substr(0)` could therefore
crash after printing the diagnostic.
Count the arity error and fill missing internal arguments with dummy constants
so elaboration can recover without building an incomplete system function call.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Check that unary real minus preserves the sign or bit pattern for zero,
NaN, and infinity. Each test starts with the positive value, negates it,
and then negates the result back to the positive value.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Currently the vvp target emits unary real minus as `0.0 - value`.
This is not the same operation for all real values. It loses the
negative zero result for `-(+0.0)` and does not reliably flip the sign
bit for NaN values whose bits are visible through `$realtobits`.
Add `%neg/wr` and use it for unary real minus. This performs a direct
negation of the real stack value, so zero, NaN and infinity all use the
same operation as unary minus instead of a binary subtraction from zero.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Check that the vvp code generator emits a -0.0 real constant with its
sign bit set, so the compiled value matches the runtime real value. The
sign used to be detected with (value < 0), which is false for IEEE 754
-0.0, and a -0.0 constant was turned into +0.0.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Check that bogus member access on a procedural l-value is rejected with a
normal compile error instead of aborting during elaboration.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Check that an invalid indexed part select base on a procedural l-value is
reported as a normal compile error instead of crashing after the bind error.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Currently the procedural l-value path asserts if symbol lookup leaves a
member tail for a variable that is not a struct or class. For example,
`r.bad = 1'b1;` where `r` is a scalar variable aborts during elaboration
instead of reporting a normal error.
Report an error for the leftover member path before the assertion. This
matches the r-value path behavior for the same kind of invalid member access.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
The l-value indexed part select path elaborates the base expression with
`elab_and_eval()`. If the base expression can not be bound this returns a
nullptr, but the l-value path dereferenced it while checking the expression
type. For example, `a[does_not_exist -: 2] = 2'b00;` reported the bind error
and then crashed.
Return early when base elaboration fails. This matches the r-value indexed
part select path and leaves the existing bind error as the reported
elaboration error.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Currently vvp_reg.py uses `returncode >= 256` to distinguish execution
errors from ordinary compile or simulation failures. That matches the encoded
status returned by wait(), but subprocess.run() does not expose that value. Its
returncode is the decoded process exit status, or `-N` if the process was
terminated by signal N. Shell wrappers can also report signal termination as
`128 + N`.
As a result a compiler crash can be reported as `-11` or `139`. Both values
pass the old check and a CE test can be accepted as a normal compiler error.
Treat negative return codes and return codes greater than or equal to 128 as
execution errors before accepting CE and EF results. Also make sure that CE gold
mismatches are reported as failures.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
The vlog95 backend currently emits `$unsigned()` when it needs to create a
self-determined unsigned expression context. `$unsigned()` is part of the
optional signed expression support in this backend and is only available when
the signed support flag is enabled.
Concatenation is part of the baseline Verilog-95 output and also creates a
self-determined unsigned expression context. Use `{expr}` for the unsigned case
and keep using `$signed()` when a signed context is needed.
Remove `-pallowsigned=1` from the existing vlog95 regression tests that now
pass without the optional signed support flag.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Check that synthesized case statement muxes can use array words as inputs.
This used to generate invalid VVP because .array/port statements were emitted
in the middle of .functor statements.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Lars-Peter Clausen
Cary R.
Ethan Sifferman
Flavien Solt